The fifth discharge of treated water from Japan's crippled Fukushima Daiichi NPP was suspended for several hours following a power outage, local media has reported. The outage occurred after as a power cable at the plant was damaged during excavation work, Kyodo reported, citing plant owner Tokyo Electric Power Company Holdings (Tepco). The system to cool reactors and used fuel pools was not affected by the power cutoff and continued to operate, Tepco said.

The incident was announced after a team of experts from the International Atomic Energy Agency (IAEA) started a second-time safety review of the ocean discharge operation that began in August last year. Despite the stoppage, IAEA was able to complete its inspection, according to Tepco. One excavation worker suffered burns and had to be treated in hospital, but the plant’s cooling systems were unaffected and the water discharge resumed safely.

Data and samples collected from the Fukushima plant will be checked at IAEA labs and independent third-party labs from China, South Korea, Switzerland and the United States, and will be released in a report later. “This independent, objective and science-based approach will help build confidence to the people in Japan and beyond,” mission leader Gustavo Caruso, director of safety and security coordination at IAEA, told Japanese officials.

The team included international experts from 10 countries – Argentina, Australia, Britain, Canada, China, France, Russia, South Korea, the United States and Vietnam. The treated water is filtered and diluted by large amounts of seawater before discharge. Results of monitoring of seawater and marine life samples near the plant show that concentrations of tritium, the only inseparable radioactive material, are far below recommended limits. The plant has released about 31,200 tonnes of the treated water in four batches. The ongoing fifth batch of 7,800-tonne release will continue until 7 May.

Opposition to the water release continues in China and from Japanese and South Korean environmental groups. Representatives from Japanese civic groups submitted over 180,000 signatures from local citizens to the Japanese government, urging both the government and Tepco to immediately halt the water discharge.

Hajime Matsukubo, secretary general of the Citizens' Nuclear Information Centre, a Japanese non-profit organisation, presented 184,712 signatures to the Ministry of Economy, Trade & Industry. The petitioning campaign, initiated earlier this year by civic groups including the Fukushima Prefecture Peace Forum under a project called Future's Ocean, or Mirainoumi in Japanese, has gained momentum, according to Xinhua.

Image courtesy of IAEA